Apparatus for making hyperbolic-paraboloidal thin shell building units



v Aug. 21, 1962 P. s. CHIADO ETAL APPARATUS F 3,049,785 OR MAKING HYPERBOLIC-PARABOLOIDAL THIN SHELL BUILDING UNITS 4 Sheets-Sheet 1 Filed Feb. 13, 1957 INVENTORS PAUL S. CHIADO JOHN A. SBAROUNIS BY @WM ATTO R N EYS Aug. 21, 1962 p, S,'CH|AD O ETAL 3,049,785

APPARATUS FOR MAKING HYPERBOLIC-PARABOLOIDAL THIN SHELL BUILDING UNITS 4 Sheets-Sheet 2 Filed Feb. 13, 1957 INVENTORS PAUL S. Cl-HADO JOHN A. SBAROUNIS BY ATTORNEYS 3 J. n m 0,.

Aug. 21, 1962 P. s. CHIADO ETAL APPARATUS FOR MAKING HYPERBOLIC-PARABOL THIN SHELL BUILDING UNITS Filed Feb. 13, 1957 VIIIIIII 1111",

T lxu IT.

INVENTORS PAUL s. CHIADO JOHN A. SBAROUNIS BY ATTORNEYS 1962 v P. s. CHIADO ETAL 3,049,785

APPARATUS FOR MAKING HYPERBOLIC-PARABOLOIDAL THIN SHELL BUILDING unn's INVENTORS PAUL s. CHIADO 55 JOHN A. SBAROUNIS ATTO RNEYS 3,949,785 APPARATUS FOR MAKING HYPERBOLIC-PARAB- OLOIDAL THIN SHELL BUILDING UNITS Paul S. Chiado and John A. Sharounis, Chicago, Ill. Filed Feb. 13, 1957, Ser. No. 640,022 4 Claims. (Cl. 25-118) The present invention relates to improvements in deck or roof or vaulted ceiling structures, and is more particularly concerned with the provision of thin shell structures of this type, of hyperbolic-paraboloidal sectional shape and a method of and means for making the same.

Numerous practical considerations warrant the extensive utilization of hyperbolic-paraboloidal sections in roof, deck or ceiling constructions, such as high compression to mass ratio, relatively wide spacing of supporting columns, small size of supporting columns due to minimum weight of the supported deck, and, of course, economy in materials.

Heretofore, an important drawback has been in the high cost of providing forms or shoring for such a structure, especially due to the compound curvatures involved.

An important object of the present invention is to provide a new and improved building structure utilizing thin shell hyperbolic-paraboloidal sections.

Another object of the invention is to provide simple, efficient method of and means for making hyperbolicparaboloidal thin wall structural units.

A further object of the invention is to provide novel shoring and forming means for producing hyperbolicparaboloidal thin wall structural forms.

Still another object of the invention is to provide novel shoring and forming means for producing multi-angular building forms.

A still further object of the invention is to provide a forming device for use in building structures and adapted for infinitely variable adjustment within a substantial range.

A still further object of the invention is to provide a reusable adjustable shoring or forming assembly for use in building construction.

It is also an object of the invention to provide a novel method of making building structures with a composite of hyperbolic-parabo-loidal thin shell units.

Other objects, features and advantages of the present invention will be readily apparent from the following detailed description of certain preferred embodiments taken in conjunction with the accompanying drawings in which:

FIGURE 1 is a more or less schematic perspective view of a building structure embodying hyperbolic-paraboloidal thin shell sections according to the present invention;

FIGURE 2 is a diagrammatic view of a shoring or adjustable form member embodying features of the invention;

FIGURE 3 is a top plan view of a shoring or adjustable frame member embodying features of the invention and showing how it is adapted to be related to companion frame units;

FIGURE 4 is a fragmentary sectional detail view taken substantially on the line IVIV of FIGURE 3;

FIGURE 5 is a side elevational view of one of the connecting flanged collar members shown in FIGURE 3;

FIGURE 6 is a fragmentary top plan view of a modified form of articulated connecting means for adjacent form assemblies;

FIGURE 7 is a similar top plan view as FIGURE 6 but showing a further modification;

FIGURE 8 is an exploded assembly view of still another modified frame bar connecting structure;

3,49,785 Patented Aug. 21, 1962 FIGURE 9 is a fragmentary top plan view of the connecting structure of FIGURE 8 showing the same assembled together;

FIGURE 10 is a fragmentary sectional detail View of a typical thin shell section showing the use therewith of the shoring or forming means of the present invention;

FIGURE 11 is a fragmentary top plan view of a modified form of frame or shoring form assembly;

FIGURE 12 is a fragmentary sectional detail view taken substantially on the line XIIXII of FIGURE 11;

FIGURE 13 is a fragmentary sectional elevational detail view of a shoring or shaping assembly utilizing the framing or form structure of FIGURE 3 in association with a building column and a thin shell hyperbolic-paraboloidal shell section already supported by the column, the structure being illustrated more or less schematically; and

FIGURE 14 is a fragmentary sectional elevational view showing a completed thin shell hyperbolic-paraboloidal structure and a supporting column, with a slightly modified arrangement.

By way of example, the more or less schematically depicted structure in FIGURE 1 shows a plurality of thin shell hyperbolic-paraboloidal units 15 supported by columns 17 and united edge to edge to provide a continuous deck or roof or ceiling structure a combination of a roof or deck and a vaulted ceiling. Each of the shell units 15 is of generally quadrangular outline and has two opposite high corners 18 and' two opposite low corners 19. The construction and arrangement are such that each outside corner of the deck has one of the columns 17 supporting one of the low point corners 19 of the adjacent corner unit or section 15. Along each edge of the deck bet-ween corners adjacent low corners 19 of adjacent pairs of the shell units or sections 15 are adapted to be supported by one of the post-s 17. Interiorly of the structure one of the posts or columns 17 is adapted to support the adjacent low corners of four contiguous units or sections 15. On the other hand, each of the high corners 13 of each of the deck units 15 joins with the contiguous high corners of the companion deck units at a peak. t will be appreciated that by the construction thus illustrated and described extremely efiicient load distribution and mutual support is attained throughout the structure. Load distribution is effectively in compression on a minimum number of columns, and since there is a well balanced condition of tension and compression in the slab, the shell sections can be constructed quite thin.

Small size hyperbolic-paraboloidal thin shell sections according to the present invention may be precast or prefabricated and then transported to the building site and mounted as the sections 15 upon the columns 17. However, where the units or sections 15 are of too large size, or other considerations prevail which substantially preclude prefabrications, but require in situ fabrication, the method and apparatus depicted in FIGURES 2, 3, 10 and 13 may be utilized. This method comprises fabrieating the thin shell deck sections 15 directly in place on the columns 17. Speed of fabrication is greatly increased by use of a novel frame unit 20* for determining substantially the hyperbolic-paraboloidal shape preferred.

For a quick understanding of the principles of construction and operation of the shoring or form assembly 20 in any of various modifications that may be embodied therein, attention is directed to FIGURE 2. Four, rigid edge members 21 of any preferred light weight beam or bar construction having substantial tensile and bendresistance strength are provided and are adapted to be connected into a quadrangular arrangement with the adjacent ends of the side frame bars connected together in 'four strands for each length of cable.

3 suitable adjustable or articulated manner by connections 22. Connected between the opposite pairs of the side frame bars 21 is supporting structure which may take a variety of forms such as molded or cast plastic, tailored fabric, metallic or non-metallic plate or mesh shaped to the desired warped quadrilateral plane, but for convenient collapsibility may comprise sets of parallel flexible strands 23, with the strands running between two of the side frame bars .21 overlapping the strands between the other two frame bars 21 in superimposed relation. The strands 23 may be of any suitable material of high tensile strength but readily flexible, such as cable, flexible metallic rod, or the like. Where rods are used, they should be of resilient flexibility so as to tend to return to a straight condition after flexing within their elastic limits. In the specific form shown, the shoring form has eight of the strands 23- running in each direction, but it will be appreciated that the number of strands may be varied as preferred depending on many factors such as the size and weight of the frame, the character of the shell or slab to be molded thereon, the conditions of use to which the frame is to be put, and the size of the frame in any given direction since, although the exemplary form is shown as square, it may be of various quadrilateral forms.

For handling and transportation, the frame assembly 20 may be collapsed and bundled or it may be handled flat for stacking with other similar frame assemblies. Then, for shoring installation, at least two diagonally opposite corners of the frame are supported, while the remaining two diagonally opposite corners may or may not be supported, as the situation warrants. In FIG- URE 2 the four corners of the frame have been arbitrarily identified as A, B, C and D. In this instance, the corners B and D are chosen to be the low corners while the corners A and C are chosen to be the high corners. The predetermined elevational attitude of the several corners is fixed by suitably locking the ends of the side frame bars 21, preferably while the crossing transverse strands 23 are in a substantially relaxed state. A compression strut 24 is preferably fixed across the top of the frame to the two high corners A and C. After these preliminaries, the strands 23 are tightened to place the same in tension. As a result of the coaction of the tensioned strands running in one direction with the strands running thereacross a substantilly uniformly hyperbolicpara-boloidal surface shape is provided between the respectively tilted frame members 21.

At the right side of FIGURE 2 is projected orthographically how the vertical strands 23, as viewed in FIGURE 2 assume their various linear relationships in the frame assembly as set for use, while at the bottom of FIGURE 2 is shown how the horizontal strands in FIGURE 2 assume their respective positions in the set frame. Orthographic projections at the lower right and lower left of FIGURE 2 show how the strands coact in producing the hyperbolic-paraboloidal surface, as viewed from the low corner B and the high corner C.

Referring to FIGURES 3 and 4, details of an exemplary form of the shoring or form frame 20 are shown. It will be observed that the side frame members or bars 21 maybe beams of H-shape cross-section. Where flexible rods are used as the strands 23, the opposite ends may be suitably secured in tensionable fashion between the respective opposite side bars 21. Where the strands 23 comprise cables, a single length of cable may provide several strands, in the particular embodiment shown Each opposite end of the cable length may be looped and engaged by a hook bolt 25 or an eye bolt extending through the flanges of one of the side frame members 21 and adapted to be loosened or drawn up by means such as a nut 27 threaded on the'shank thereof for relaxing or tensioning the cable. Intermediate portions of the cable length are looped over respective brackets 28 carried rigidly by the inner sides of the respective side bars 21. slackening ofi of the cable can be readily effected by loosening the respective connecting bolts 25 and tightening of the cable can be readily effected by tightening the bolts.

At their opposite ends, the frame bars 21 may be provided with respective clevis-like terminals 29 that are attachable by means of pins or bolts 30 to respective ear or fin flanges 31 radiating in longitudinal planes from the respective corner connectors, in this instance in the form of tubular or sleeve members. The construction and arrangement is such that the connecting elements or bolts 30 can be tightened to secure the frame bar terminals 29 substantially fixedly in the preferred attitude of angular adjustment of the respective frame bars.

It will be appreciated that through this arrangement the several frame bars are adjustable for attaining hyperbolic-paraboloidal curvatures infinitely throughout a substantial range.

Various articulated connection devices other than the winged sleeve 22 may be utilized, such for example, as in FIGURE 6 wherein a separable split ring 32 is utilized for connecting the terminal portions of the side frame members 21. In FIGURE 7, another form of split ring connector 33 is shown for connecting the terminal ends of the frame bars 21 of a pair of the frame members, the ring being of angular form with each of the angular pieces that is engaged by the side bar terminal being separable with respect to the other pieces.

In FIGURES 8 and 9 another form of terminal connector structure for the side bars is shown wherein the terminal bifurcation or clevis 29 is provided with a downwardly opening notch 34 engageable in straddling rel-ation over a ring shaped connector 35 that has fixed thereon a grip plate 37 which is disposed between the two arms of the clevis. A pair of complementary clamping plates 38 having upwardly opening notches 39 therein straddlingly engage about the ring connector member 35 and are secured in clamping relation upon the respective outer sides of the clevis arms by means such as screws or bolts 40 upon which are threaded nuts 41, the clevis arms and the clamping plates being provided with matching screw holes therethrough to receive the shanks of the screws 40. When the nuts 41 are drawn up tight on the screw shanks, as seen in FIGURE 9, a separable connection of the frame terminal to the ring connector 35 is effected.

Another arrangement for effecting tensioning of the strands 23 is shown in FIGURES l1 and 12 and is especially suitable for large size frames. In this arrangement, the strands 23 extend through one of the side frame members 21 while the opposite ends (not shown) are fixedly attached to the opposite frame member. For tensioning purposes, the end portions of the strands or cables 23 that extend through the frame member 21 are anchored as by means of anchor devices 42 to a jacking beam or bar 43, while jack members 45 are mounted between the opposing sides of the jacking beam and the adjacent side member 21. Through this arrangement, slacking off and tensioning of the strands 23 is facilitated.

In order to take advantage of the high compression strength of the hyperbolic-paraboloidal thin shell construction, the low corners of the respective shell units 15 are as shown in FIGURES l and 13 supported on the columns 17. Hence, in erecting the shorting frames 20, the low corners thereof are supported on the respective columns 17 in a manner to be removed for reuse after the shell unit 15 has been completed. Each of the columns 17 may be provided with an enlarged head 47 providing a substantial crown upon which is centrally supported one of the frame terminal connectors, such as one of the sleeve or collar connectors 22 (FIG. 13), by an upstanding central stud member 48 about which the sleeve connector member 22 is slidably mounted. Anchor bolts 49 may be utilized to secure a base flange 50 of the stud member 48 detachably upon the crown of the column head 47. Elevation of the sleeve connector 22 with respect to the base flange 50 may be determined by a flange plate 51 of proper thickness, or a plurality of such flange plates disposed removably about the stud column member 48 under the lower end of the sleeve connector 22.

It will be understood that in view of the nature of the form frame members 20 and the manner in which they are adapted to be secured in complementary, working association, two of the slabs or shells 15 can be constructed at the same time to rest upon any one column, and thereafter if two more of the shell units 15 are to be supported by the same column to fill the gaps between the first constructed shell units, the storing frames 20 may be reassembled in the gaps. For example, in FIG- URE 13 a completed shell unit 15 is shown as having an end thereof supported on the crown of the column head 47, while immediately adjacent to the opposite sides of the shell unit 15 two of the shoring frames 26 have been mounted, one of such frames being partially omitted for clarity of illustration, and while there may be another of the completed shell units 15 at the opposite side of the column head 47, that has also been omitted for purpose of illustration.

Any preferred cementitious or plastic material may be used in constructing the shell units 15. Cement or concrete aggregate may be used, and the method of the present invention lends itself especially well to gun application of the cementitious slurry. To this end, after the shoring frames 20 :have been erected and adjusted, with the strands 23 properly tensioned to aiford the desired hyperbolic-paraboloidal supporting base, an tmderlayment pad 52 of any suitable material that will conform to the multi-angular curvature of the supporting strands 23 is placed conformably thereover (FIGS. and 13). At the respective corners of the shoring frame form, end form members 53 may be used as extensions of the underlayment. Over the underlayment may be placed in any preferred manner, reinforcing rods or mat means 54 in such a way as to be completely embedded in the completed shell slab. Then the slurry is applied to the form in the thickness desired and allowed to set for the usual length of time. Thereafter the shoring form is removed from each of the finished shell units 15. Any preferred tie-in reinforcement between the column shoulder or head 47 and the end abutments of the respective shell units may be employed in accordance with preferred construction or reinforced concrete practice.

After the shell units to be supported by any one of the columns 17 have been completed, gaps between the adjacent edges of the shell units may be filled in or closed in any preferred manner, such for example as by closing the undersides thereof and filling the same in with grout. If desired, pipes, or wiring conduits or the like may be mounted in the gaps or spaces before the same are closed over. For example, in FIGURE 14 is shown how the gap between two adjacent of the shell units 15 has been filled in with grout at G, thus providing a jointfree surface. Of course, extensions of the reinforcing means 54 at the sides of the shell units may be extended into or across the edge gaps and thus tie the entire shell structure into a monolithic unit on completion.

Where it is desired to utilize the depression between the supported ends of the shell units 15 on the column crown as a drain sump, a drain pipe 55 may be provided to run longitudinally through the column 17 and the head 47 with a month end opening through the crown of the head. Then a drain screen 57 may be fitted on the mouth end of the drain pipe 55 and if desired grouted in as shown in FIGURE 14.

If desired, the upper or column crown end or mouth end of the drain pipe 55 may normally extend a short distance above the crown of the column head and be utilized as a stud column centering means as indicated in 6 dot dash outline in FIGURE 14. Thereby elimination of anchor bolts such as the anchor bolts 49 is enabled. Finally of course, the drain screen 57 may be applied over the upstanding extremity of the drain pipe, and the sump bottom grouted in to a proper level for drainage into the screen.

Because of their flexibility, the strands 23 may be subject to some degree of catenary in service. However, any slight or nominal variables from perfect hyperbolicparaboloidal planes thus caused in the finished shell units will not detract from the general results intended. Therefore, such catenary variables are included in the term hyperbolic-paraboloidal as used herein.

Inasmuch as the shoring frame units 20 can be reused indefinitely, it will be appreciated that shoring costs are greatly minimized by the use of shoring frames according to the present invention. Due to the ease of erection and uniformity of results that are attainable by use of the present invention, not only are labor costs held to a minimum, but a consistent uniformity in results can be attained with minimum usage of materials.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

We claim as our invention:

1. In apparatus for making hyperbolic-paraboloidal thin shell building units, a quadrangular frame comprising substantially rigid side frame bars relatively oriented With their respective ends in adjacency, articulated connecting means by which the ends of said side frame bars are attached in angular adjustable relation whereby the bars are adjustable to place two opposite corners in an elevated relation to the remaining two opposite corners throughout a substantial range, flexible strands connected in substantially straight respective lines between two of the bars and flexible strands connected in substantially straight respective lines between the remaining pair of bars, means for placing the strands under tension after the corners have been relatively disposed with two of the corners elevated and two of the corners depressed, whereby to form a hyperbolicparaboloidal supporting plane upon the strands, a compression strut and means connecting the ends of the compression strut to the elevated corners whereby the strut retains such corners in position under the tension of the strands, and underlayment supported conformably to said supporting plane provided by the strands and supportive of material to be molded into a hyperbolic-paraboloidal form thereupon.

2. In apparatus for making hyperbolic-paraboloidal thin shell building units, a quadrangular frame comprising substantially rigid side frame bars relatively oriented with their respective ends in adjacency, articulated connecting means by which the ends of said side frame bars are attached in angular adjustable relation whereby the bars are adjustable to place two opposite corners in an elevated relation to the remaining two opposite corners throughout a substantial range, flexible strands connected in substantially straight respective lines between two of the bars and flexible strands connected in substantially straight respective lines between the remaining pair of bars, means for placing the strands under tension after the corners have been relatively disposed with two of the corner-s elevated and tWo of the corners depressed, whereby to form a hyperbolic-paraboloidal supporting plane upon the strands, means connected to said elevated corners and retaining such elevated corners in the elevated position under the tension of the strands, and underlayment supported conformably to said supporting plane provided by the strands and supportive of material to be molded into a hyperbolic-paraboloidal form thereupon.

3. In apparatus for making hyperbolic-paraboloidal thin shell building units, a quadrangular frame having substantially rigid and straight side frame bars, means comprising articulated connections by which the ends of the side frame bars are attached together with two opposite corners of the frame being arranged to be elevated and the two remaining corners of the frame depressed relative to the elevated corners throughout a substantial range supporting structure comprising a first set of flexible strands connected to and between two of the frame bars and a second set of strands freely lappingly crossing said first strands and connected to and between the remaining two bars, means for tensioning said two sets of strands after the corners of the frame bars have been relatively elevated and depressed so that together the two sets of strands provide a substantially hyperbolic-paraboloidal form plane receptive of underlayment conformed to said hyperbolic-paraboloidal form plane and supportive of moldable material within said frame and conformed to said hyperbolic-paraboloidal plane, and means connected to the elevated corners of said frame to hold said corners substantially rigidly in position under the tension of said sets of strands.

4. In apparatus for making hyperbolic-paraboloidal thin shell building units, a quadrangular frame having substantially rigid and straight side frame bars, means comprising articulated connections by which the ends of the side frame bars are attached together with two opposite corners of the frame being arranged to be elevated and the two remaining corners of the frame depressed relative to the elevated corners throughout a substantial range, supporting structure comprising a first set of flexible strands connected to and between two of the frame bars and a second set of strands freely lappinglycrossing said first strands and connected to and between the remaining two bars, means for tensioning said two sets of strands after the corners of the frame bars have been relatively elevated and depressed so that together the two sets of strands provide a substantially hyperbolic-paraboloidal form plane receptive of underlayment conformed to said hyperbolic-paraboloidal form plane and supportive of moldable material within said frame and conformed to said hyperbolic-paraboloidal plane, and a compression strut connected between the elevated corners of said frame to hold said corners rigidly in position under the tension of said sets of strands.

References Cited in the file of this patent UNITED STATES PATENTS 1,215,318 Cook Feb. 6, 1917 1,241,945 Fletcher Oct. 2, 1917 1,630,839 Fisher et al May 31, 1927 1,830,606 Kandle "a Nov. 3, 1931 1,864,043 Gruber June 21, 1932 1,940,402 Dischinger et al Dec. 19, 1933 1,947,360 Roos Feb. 13, 1934 1,949,220 Schick Feb. 27, 1934 2,170,564 Lundin Aug. 22, 1939 2,353,073 Pitou July 4, 1944 2,522,116 Hayes 2 Sept. 12, 1950 2,578,057 Flores Dec. 11, 1951 2,616,149 Waller Nov. 4, 1952 2,787,042 Breguet Apr. 2, 1957 2,891,491 Richter June 23, 1959 2,948,047 Peeler et a1 Aug. 9, 1960 OTHER REFERENCES Hyperbolic Paraboloidal Shells, Journal of the Amer.

Concrete Inst, January 1955, pages 397-415. 

